The NIH Roadmap emphasizes how the discovery of bioactive "small molecules" can help both in the exploration of "cellular functions at the molecular level" and the development of new drugs. Reflecting the importance of such molecules, one of the Molecular Libraries Roadmap's Initiatives is to support the construction and screening of small molecule libraries. Small molecules and peptides support retinal ganglion cell (RGC) survival and neurite outgrowth by modulating various cellular signaling pathways. Identification of additional such molecules is the focus of this grant. Forskolin and BDNF are examples of molecules that that were originally found to support RGCs in culture and later demonstrated to have efficacy in animal models of optic nerve injury. Identification of novel small molecules that support RGCs in cell culture offers two potential benefits. Such molecules will make possible new lines of inquiry into RGC function at the molecular level. Secondly, factors supporting RGCs in cell culture are a logical source of candidates that may have translational, therapeutic benefit in preserving or restoring vision in patients with blinding optic nerve diseases such as glaucoma, optic nerve stroke, and optic neuritis. Small molecules have potential advantages compared to larger molecules, such as proteins, in that they may be more readily developed into drugs and may be more easily delivered to the eye. A rational and comprehensive way to identify functionally interesting small molecules is to combine a sensitive bioassay with a high throughput screen. We have successfully initiated such a screen, assaying cultures of immunopurified rat RGCs with an automated fluorescence-based image analysis system that measures cell survival and neurite outgrowth. The objective of this proposal is to expand this screen so as to identify, validate, and optimize novel pharmaceutical compounds that promote survival and regeneration of RGCs. More specifically, this grant will support the continued survey of a "small molecule" library for RGC survival and neurite outgrowth factors, confirm the bioactivity of those hits by demonstrating a dose response relationship, and further determine the essential element that exhibits the bioactivity. Reagents identified in the screen will be the subject of future hypothesis driven research to characterize their mechanism of action in vitro and further explore their therapeutic potential in vivo. [unreadable] [unreadable]